Gauge



s. Y. lWHITE Mziy 7, 1946.

GAUGE 5 Sheets-Sheet 1 Original Filed April 18 1942 IN VEN TOR. .5w/varK ri/ms May 7, 1946.

s. vY. WHITE GAUGE original Filed April 1s, 1942 S'ShtS-sheet 2 f/qf. M

Taiiu;

s. Y. WHITE 2,399,703

GAUGE May 7, 1946.

`Origine-.l Filed April 18, 1942 5 Sheets-Sheet 5 lol May 7, 1946. a YWHITE l 2,399,703

GAUGE Original Filed April 18, 1942 5 Sheets-Sheet 4 s. Y. wHrrE:

May 7,1946.

@AUGE Original Filed April 18, 1942 I 5 Sheets-Sheet 5 Patented May 7,1946 GAUGE Sidney Y. White, Wilmette, Ill., assignor to Victor S.Johnson, Chicago, Ill.;V

Alex Thomson administrator of said Victor S. Johnson, deceased originalapplication April 1s, 1942, serial No. 439,509. Divided and thisapplication March 10, 1944, serial No. 525,387

2 Claims. l (Qi. 33--165 The present application is a division of mypending application, Serial No. 439,509, filed April 18, 1942, forDevice for adjustingV or tuning to close limits.

In' my parent application disclosure is made of means for adjusting anoperated member to close limits which is of general application andwhich is illustratively disclosed as embodied in tuning means for tuningaV radio circuit and also as em bodied in a gauge for gauging the sizeof articles.

Claims directed broadly to a combination of adjusting means of generalapplication' and to a radio tuning means are included in said parentapplication. Claims directed to a spacing device per se which isadvantageously employed in said combination are included in anotherydivisional application Serial No. 525,886, executed and filedconcurrently herewith and entitled Spacing device for adjusting to closelimits. The present application is directed to gauging means.

The primary object i the present invention vis to provide a gaugecomprising relatively xed and movable members, together with a spacingmember which may be quickly and conveniently set to adjust the movablemember to any one of a multiplicity of selected mechanically determineddatum positions, each representing a known and accurately indicatedspacing of the movable member from the fixed member, and an operatingmember having a limited range of continuous movement, by means of whichthe movable member may be adjusted micrometically throughout a selectedrange which depends upon and includes the selectedmechanicallyfdetermined datum setting.

In the illustrative embodiment of the invention, the spacing member isprovided with a, plurality of steps adapted to impart successive stepsof movement to the operated member, which move` ments are equal to eachother, and also equal substantially to the limited range of movement ofthe operating member. Such relationship is not necessary, however, forthepractice of the invention, and it will be understood that for certainpurposes the several steps of the spacing member may be unequal and alsothat the limited amount of movement imparted to'thefoperated` member bythe actuation of the operating member spacing member.

due to its displacement by the operating, member and the reading of thedial associated with the spacing member indicating the setting of theoperated member due to its displacement by the The sum of the readingsof "the two dials indicates the setting of the operated member resultingfrom its displacement by both the operating and spacing members in anycasewhere both the latter members are operated. The described dialarrangement provides a very extensive effective dial surface yet at thesame may be more or less than any one step of rn'ovement imparted to theoperated member in response to the movement of the spacing member.V Itis a further object of the invention to` provide in association ywitheach of such operating. and spacing members a dialvdevice, the readingof the dialasscciated with the operatingmember indicating the setting ofthe operatedmember;

time takes up only a small amount of space, is easily read and isinexpensive to manufacture. Further advantages of such a dual dialarrangement will become apparent as its application for indicating thesetting of a movable gauge member is described.

Let it be supposed that a gauge is desired capable of measuringaccurately to within .0001 inch of thickness throughout a range of .2500inch, and of` affording a reasonably dependable visual approximation tothe limit of .00002 inch.

For indicating the setting by means of a dial mechanically connected tothe movable member it has been found that dial divisions spaced 0.1

inch apart are easy to read and admit of reasonably accurate visualinterpolation to the neness of one-fth of a dial division. If each dialdivision of 0.1 inch corresponds to a gauging increment lof .0001 inch,a total of 2500 Vdivisions would be required to cover the total gaugingrange of .2500 inch and a total dial length of 250 inches would berequired. `This would require a single dial having a diameter ofapproximately inches. Such a dial is-obviously commercially impracticalon'accourt of its large size, weight and cost. It is an important objectof the present invention to provide an easy reading dial arrangementconstructed upon a principle such, for example, that a pair of dials ofonly 4 inches in diameter provide the equivalent of .approximately 25ft. of dial length.

In the preferred embodiment of the invention, the' two dialsareconcentrically mounted for rotationaboutia common axis so that theentire adjusting and indicating unit may be made very compact and lightin weight. The movable gauge member is mounted on a push rod which isactuated by a lever from a pointnear the lever fulcrum, the outer `endof the lever being rocked by a coarse pitch screw which carries a dialcontinuously calibrated over approximately 270 of its periphery from 0to .0,100 inch. The pitch of the screw and the lengths of the lever armsare vsuch that` the thrust rod is moved `a distance .0100

inch for a rotation of the dial of 270. The calibrated portion of thedial has 100 equal divisions, each representing a movement of the thrustrod, of .0001 inch. By using a coarse pitch screw and rotating itthrough less than one revolution, the back lash and inaccuracy resultingfrom the use of a very fine pitch screw rotated through severalrevolutions is avoided, it being a very difficult and expensiveoperation to cut screws of fine pitch without variations in pitchbetween the different turns.

The initial spacing of the relatively fixed and movable gauging members,which may illustratively be taken as zero, is indicated on a second dialprovided immediately adjacent the first and hereinafter described.Thisinitial spacing is controlled and determined by the interpositionbetween the operating member and the thrust rod of a spacer block ofknown thickness. If the continuous dial is operated from this initialsetting of zero throughout its entire scale to a reading of 100, thespacing between the gauging members will have been increased from zeroto .0100 inch. If now the continuous dial is returned to zero and aspacer .block is substituted whose thickness is less than that of thefirst by .0100 inch, the push rod will be again caused to occupy exactlythe same position to which it was operated by the continuous dial withthe first spacer block in effective position. The continuous dial maynow be again operated through the one hundred divisions representing itstotal scale to cover an additional range of .0100 inch, to wit, from.0100 to .0200 inch spacing of the gauging members. By the repeatedsubstitution of spacer blocks, each having a thickness of .0100 inchless than that of its predecessor, the range may be extended again andagain.

It is a primary feature of the invention that a series of spacer blocksis provided in the form of a stepped floating cam which is rotatablymounted so that any desired spacer block -may be quickly interposedbetween'the lever and the end of the push rod. The second dial and thestepped cam are connected for coordinated operation, the second dialbeing calibrated to indi; cate the separation of the gauging members forwhich the cam operation is responsible. Thus, each step of the cam andthe second dial represents a spacing increment of .0100 inch comparedwith its neighbor, while each division of the first dial represents1/ino of a single step of the second dial. The combined setting can bevery readily read off the two dials, since the reading of the iirst dialis always a decimal fraction of the unit in which the second dial iscalibrated, this unit being .01 inch.

It is a further important feature of the invention that provision ismade for adjusting the thickness of each spacer block so that each stepof the stepped cam may be made to differ in thickness from its neighborsby exactly .0100 inch. In the illustrative embodiment of the invention,each step of the cam is provided with an adjusting screw so that thethickness of each step may be readily and precisely adjusted to thedesired value.

It is a practical and advantageous feature of the invention, that astepped cam is provided having a hard wearing surface on each step inthe region where it engages th'epush rod. The hard surfaces aredesirably provided by setting hard steel balls into the respectivesteps. By providing a transverse groove in the end of the push rod sothat it engages each ball at two spaced points on the curved surface ofthe ball and by biasing the push rod against the ball by means of aspring, a good detent action is secured which assists in setting eachball in proper position against the push rod. Furthermore, the wear doesnot all take place at the high point of each balls surface as would .bethe case if the end of the push rod were fiat and rested against the endor high points only of the balls.

' It is an important object of the invention to v provide a gauge devicein which two adjusting units of the type heretofore described aremounted together to form a go-no go gauge for the'purpose of testing thesizes of a plurality of similar articles to insure that each comeswithin an allowable tolerance. Such a gauge has a large field of utilityin cases where only a relatively small number of articles are to betested and yet where the tolerance limits are small so that a highdegree of precision in measurement is required.

Further objects of the invention will become apparent as the descriptionthereof proceeds. For a better understanding of the invention, referenceis made to the following description, taken in connection with theaccompanying drawings, in which;

Fig. 1 is a top plan view of a gauging device embodying features of theinvention;

Fig. 2 is a fragmentary front view showing on an enlarged scale aportion of the front panel and indicating dials of the gauging device;

Fig. 3 is a fragmentary horizontal, sectional view showing the operatinglever and a portion of the adjusting screw;

Fig. 4 is a vertical sectional view taken on the line 4-4 of Fig. 5looking in the direction of the arrows and showing the adjusting screwmounting and operating lever;

Fig. 5 is a plan view partly in section showing further details of themechanism illustrated in Fig. 1; A

Fig. 6 is a vertical sectional view taken on the line 6 6 of Fig. 5showing portions of the adjusting device;

Fig. 7 is a sectional view taken on the line 1 1 of Fig. 5 looking inthe directionrof the arrows and showing portions of the adjusting screwand the dial mountings;

Fig. 8 is a fragmentary, vertical, sectional view showing the supportingnut for the .adjusting screw;

Fig. 9 is a rear view, partly in section, showing on an enlarged scalethe construction of the floating cam and a portion of its driving gear;

Fig. 10 is a vertical sectional view taken on the line lll-l0 of Fig. 5,showing on an enlarged scale the operating lever, the floating cam, andthe end portion of the thrust rod;

Fig. `11 is a front view taken from the left of Fig. 12, showing on anenlarged scale the construction of the Iloating cam;

Fig. 12 is a vertical sectional view taken on the line I2-l2 of Fig. 11looking in the Vdirection of the arrows and showing the construction ofthe floating cam and its operating lever; and

Fig. 13 is a fragmentary, vertical, sectional view showing on a reducedscale a modiedform of cam construction, the rear face of the cam beingpartly broken away.

Referring to Fig. 1, the invention is shown in connection with a go-nogo gauge which desirably comprises duplicate gauge devices adapted tobe'independently loperated to different desired settings. As. thesegauge'devices appear in Fig. 1, the lower one willbe described, butsince the upper gauge device is a duplicate of the lower one the samereference characters have been applied to corresponding parts with aprime mark v added in each instance, and the description of the lowergauging device may be taken as equally applicable to the upper gaugingdevice throughout. The structure comprises a base |41 upon which all ofthe other structure is supported and mounted. A supporting standard |Iis secured to the base |41' by screws |52 and has threaded through itrelatively xed gauge `screws |50 and |50'. Suitable lock nuts |54 and|54' are pro vided for lockingl the respective screws |50 and |50 indesired positions. The screws |50 and |50 are provided at the tips withgauge blocks |58 and |58', respectively, of hard material as, forexample, carboloy, some hard steel; hard chrome plate or nitrided steel,and the faces ground flat and polished. Opposed to the gauge blocks` |58and |58', respectively, are similar gauge blocks |56 and |56 which arefixed, respectively, upon movable thrust rods 2| and 2| of the lower andupper gauge devices. The remainder of the mechanism to be described i'sfor supporting the thrust rods 2| and 2|', for operating them,respectively, toward and from the gauge blocks |58 and |58', and forindicating the settings established by such operation.

The supporting structure comprises an intermediate vertical panel |3 anda front panel I4 which is secured to the intermediate panel I3 by meansof tubular sleeves I5 and screws I6. The intermediate panel I3 issecured by screws* |48 to lugs |46 provided on the supporting base |41.A rear vertical panel 55 is similarly secured by screws |48 to lugs |46provided on the base |41. A casing member 3| is interposed between thepanels I3 and 55 and secured to them, forming with them a closedhousing.

Both lower and upper push rods 2| and 2|', as well as the associatedmeans for operating the rods and for indicating the spacing adjustmentsthereof are carried by the frame structure described.

The lower gauge comprises a pair of control knobs I1 and I8 which aremounted in front o1 the panel I4, these knobs being secured to a pair ofshafts I9 and 20 (see Fig. 5) which extend rearwardly and are adapted tooperate the push rod 2| through connections to be hereinafter described. The knob I1 carries a stop pin 22 which is adapted .to engageanelongated abutment 23 (see Fig. 2) secured to the panel I3 for thepurpose of preventing the rotation of the knob `I1 through a full 360.

The rod 2| is biased forwardly with a force preferably of a pound ormore by means of a spring |50 which is a short spiral spring of increasing radius, as shown, the small endl of `theA spring engaging adisc |80 secured to the push rod 2|. The large end of the spring |59 isan-` chored against the rear wall of panel` 55 by means` of a generallyconical casing IBI which is secured to the plate 55 by screws |62. Thecasing I6I at its rear end is bored, as at |63, to form a supporting hubfor the push rod 2|. To prevent rotation of the rod 2| during itslongitudinal adjustment, it is provided along its topportion near itsfront end with a groove 52 (see Fig. 5) inl which a ball 53 is seated,the ball being `carried by bushing 54. The bushing 54 is secured to therearA wall of 55 by screws 56 -and serves .to support and guide 4the rod2| during its longitudinal adjustrnent;` j x '15, ber 82 whoseright-hand end is solid asv shown in.

. gear Referring to Figs. .1, 5, and, the front end of `rod 2| engages afloating cam C which is mounted for. both rotative and longitudinalmovement. The cam is rotated by means of a wheel 51 secured to a shaft20, this gear engaging a toothed gear 58 carried by the peripheral faceof the camlC. Rotation of the cam C by the knob I8 and the gear 51serves to adjust the thrust rod 2| in a manner to be later described.The cam C is also adapted to be moved bodily in the direction of thelength of the thrust rod by means of a lever L which is pivoted near itsright'end on a pin 59. An intermediate point on the lever carries a ball60 which bears against the front face ,of the cam C, and the left end ofthelever moved rearwardly by means of a coarse pitch screw 8| formed A`detailed description of the screw 8| and the means for indicating itsposition of adjustment will flrstbe given.

Referring to Figs. 5, '1, and 8, the threads of the screw 6| engagecorresponding and spaced apart threaded portions 52 and 63 formed on theinterior of a supporting nut 64 which is secured to the panel I3 byscrews 65. The central portion of the nut `(i4 is cut away, as indicatedat 68, to clear the screw 6I and is also transversely slotted, asindicated at 61, to make the end portions of the nut more flexible. Thefront and rear ends of the nut are longitudinally slotted and providedwith spaced downwardly extending arrns`68, 89 which are adapted to bedrawn together by screws 10 (see Figs. 4 and 8), By supporting the screw6I near its ends, vertical or sidewise motion thereof which might movethe lever L slightly is prevented, and by adjustment of vthe screws 10,rm engagement of the threads on the end portions 62--63 of nut 64 withthe threads of adjusting screw 6I is assured, it being possible by meansof this construction to take up any small amount of looseness orbacklash Which-,might exist.

As shown in Fig.` 5,`the knob I1 has an integrally formed sleeve`portion 1| which is secured to shaft I0 by a screw 12,. the sleevebeing slotted to receive apin 13 carried by a collar 14, see Fig. 7also, which therefore rotates with the knob I1. At its front end thecollar 14 has secured thereto a thin circular dial 15 which has 100graduation divisions which extend through 270 as shown in Fig. 2, Thedial reading appears in a window opening 16 in panel I4 which isprovided with index marks 11 and, in the illustrated embodiment of theinvention, each division of dial 15 represents .0001 inch.

Mounted behind and concentric with the dial 15 is a second dial 18 whichis secured to a collar 18 rotatable on the collar 14. The graduations`on the dial 18 are spaced apart by a substantial distance, asshown inFig. 2, and also appear in the window openings 16, each graduationrepresenting .0100 inch. For rotating the `dial 18 its periphery isprovided with gear teeth 80 which engage and are driven by the teeth ofa gear 8| secured to the shaft20, see Figs. 2 and 5. In order to preventthe rotation of the dial 18 throughA a complete revolution, a stop pin19a projects from the rear face of the collar 19, seeY Fig. 7, this pinbeing adapted to strike against thescrew 10 when dial 18 is rotated inone direc.

tion and against the depending arm 68 of nut 84 when the dial is rotatedin the opposite direction,

Referring to Figs. 3,4, and 5, the lever L comprises a generally channelshaped pivoted memon the shaft I9.-

Fig. 3, the pivot pin-59 passing through the solid portion and alsothrough the upper and lower side walls 83, 84 of a channel shapedsupporting bracket 85 whose front wall is secured to the panel I3 by thescrews 86. The pivot pin 59 is a tight rit for the holes in the pivotedmember 82 and the upper and lower channel walls 83-84 to prevent anylost motion in pivoted member 82 as it oscillates. oted member 82 is cutaway silghtly so as to clear the upper and lower walls 83-84 butthe endportions of these walls engage the upper and lower walls of the pivotedmember 82 at all times thereby preventing any lost motion in an upwardor downward direction of the pivoted member 82 about its pivot pin, Thepivoted' member 82 is constantly biased toward the adjusting screw 6| bymeans of an elongated at spring 81 which is bent into the form shown inFig. 3 and whose right-hand end is secured to the base of the channelbracket 85 by the screws 88 and thin plate 88a. The other end of thespring bears upon a pin 89 which extends between the upper and lowerwalls 90 of the channel member 82. Near its right-hand end the channelmember 82 carries the ball 60 which engages the cam C while near itsleft-hand end it is provided with a bore adapted to receive a threadedscrew 9| provided with a lock nut 92. The head of screw 9| is formed asa steel button 93 whose front surface bears against a steel ball 94which is partly embedded in the end of the screw 6|. To prevent wear ofthe button 93 its front face is preferably polished and lapped and hardchrome plated. The pitch of the screw 6| and the proportions of the armsof the lever L are such that when the knob I1 is rotated from thegraduation Zero to the graduation 100 on dial 15, the ball 60 will movethe cam C and push rod 2| rearwardly a distance of exactly .010 inch.

Referring to Figs. 9 to 12 for a detail description of the cam C, thisis shown as comprising a generally disc shaped cam member 95 whose rearface is provided with 26 steps of increasing thickness, a steel ball 96being secured in each step in a manner to be later described. The camdisc 95 p is preferably formed as a die casting of an alloy consistingof 90% aluminum, 4% copper and 6% silicon. This alloy is readily adaptedto the die casting process and is at the same time very tough, durableand corrosion resistant. The balls 96 are of the same diameter and aredisposed at the same radius from the center of rotation of the cam disc95. The bearing face of each ball is disposed at an elevation of exactly.010 inch from that of the next adjacent ball and the balls are adaptedto come successively into engagement with spaced apart points 91 of abutton 98 formed of carboloy and which is brazed to the end of the pushrod 2|. The spaced bearing points 91 are provided by cutting ahorizontal V shaped groove 99 in the end of the button 98, whichconstruction results in most of the abrasion and wear on each ball 96,occurring at the high point of the ball which is not a gauging point,the amount of abrasion and wear on the gauging points of the ball beingrelatively small. The provision of the groove 99 also eliminates minorerrors which might otherwise be caused by small variations in the radiusof the balls 96 from the center of the cam disc 95. The constructionalso provides a good detent action, since if the cam disc 95 is notmanually adjusted to exactly the correct position, that bearing point 91whichis in engagement with the sloping surface of a ball 96 will Thecenter portion of the piv' ride down such surface under the bias of thespring |59 thereby exerting a camming action on the cam disc whichrotates it a slight amount into the correct position. In such positionboth the bearing points 91 are in engagement with the surface of theball, as shown in Fig. 10.

The upper face of the button 98 is ground to an arcuate shape asindicated at |00 to provide a better camming action as the nextsucceeding ball comes into engagement with and slides along such surfaceduring the movement of the push rod rearwardly, thus facilitating theadjustment of the rod 2|. The lower face of the button is rounded offslightly, as indicated at I 00a, for a similar reason.

The cam disc 95 is secured to the front end of shaft IOI whose rear endis mounted for both rotation and longitudinal movement in a bearing |02which is secured to the casing wall 55 and which extends into an opening|03 provided in the casting 32, see Fig. 12. The front end of the shaftIOI is formed as a large cylindrical disc |04 whose rear surface isundercut as indicated at |05, Fig. 12. An intermediate portion of theshaft IUI is threaded as at |06 and a cooperating lock nut |01 isprovided. The front face of the cam disc 95 is also undercut at I 08 toprovide an annular face |09 which comes opposite the annular face IIO ofdisc |04. Mounted between the disc |04 and cam disc 95 is a thin steeldisc I I I whose center portion is solid and whose outer portion isprovided with a plurality of radial slits H2 which extend from justwithin the border of the annular faces I09-I I0 clear to the outer edgeof the disc I II thereby providing a plurality of bendable leaves II3one of which comes opposite each of the balls 96. Before assembly thesteel disc II I is hardened and the center portion thereof is thenannealed to render the material in the central region somewhat flexibleso that each leaf I I 3 may be bent slightly independent of the otherleaves, the material throughout the major portion of the leavesremaining hard, however. Cast in the front face of the cam disc 95opposite each of the balls 96 is a groove the lower portion of which issemi-cylindrical as indicated at I III (Fig. 11) and Whose outer portionis tapered in the shape of a cone as indicated at I I5 and having thesame taper as the head of an adjusting screw II6. This screw ispreferably provided with a hard screw-threaded portion II1 adapted tocut its own threads in the groove II4 and the outer end of the screw isrounded olf slightly, as indicated at II6a, so as to prevent the .end ofthe screw from cutting into the metal of cam disc 95. Referring to Figs.10 and 12, it will be obvious that the distance between the bearingsurface of the ball 69 on lever L and the bearing surface of each of theballs 96 of cam C Imay be adjusted by a slight amount by rotating thescrews I I6. From Figures 6, 10 and 12 it will be observed that thelever L extends horizontally across the centerr line of shaft IOI sothat the slight sidewise movement of. the ball 60 caused by theoscillation of the lever exerts only a radial component of force on thedisc III so that the oscillation of lever L has no tendencyto rotate thecam disc 95 which would in turn displace the push rod 2I by a very smallamount but, nevertheless, into an incorrect position.

The method of making the cam forms no part of the present invention, andis fully described in my parent application hereinbefore referred to.

Briefly however, it may be noted that the h'ard balls are placed inbores of the cam block and simultaneously embedded in the relativelysoftmetal of the cam block by at press which comprises a multiplicity ofplunger pins, each adapted to engage one of the balls and to force itinto the cam block to precisely a predetermined depth, the pins beingvaried in length so that successive balls standV atsuccessiveelevations, the increment in elevation being uniform and ofprecisely determined magnitude. The pins act also to swage the metal ofthe cam block in around the balls, for retaining the balls firmly inplace.

The operation of placing the balls in the openings |4| in cam disc 95and of pressing the balls into the disc by the press is carried on in anair conditioned room from which dust and dirt particles have beenremoved. The cam disc 95 with its attached balls 96 is placed in aheated oven where it is heated to a temperature slightly above 400 F. torelieve any internal strains which may have been set up in the metal ofthe cam disc.

VAll the balls used in the gauge device are preferably made of polishedsteel which has been nitrided to harden them and render them corrosionresistant. All the bushings which support the rotary shafts as well asthe threaded nut 64 and the hub 54 which supports the push rod 2l arepreferably made of bronze. The remaining members of the gauge device(except those above specified as being of different materials), arepreferably of Duralumin or other metal which is highly resistant tocorrosion as, for example, stainless steel, bronze or Monel metal.

It will be understood that if the gauge blocks are in contact at minimumspacing, both dials should read at that time, but that the dial readingsincrease as the space between the gauge blocks is increased in responseto the forward movement of the push rod 2|. If the divisions on theouter dial 18 are, for example, 0, .0100, .0200, .0300, etc., inch, andthe inner dial is graduated so that each division is equal to .0001inch, then the spacing between the gauge blocks |56 and |58 may bereadily determined by merely adding together the readings of the twodials. For example, if the outer dial reads .0100, or simply .01, andthe reading on the inner dial is 5, then the distance between the gaugeblocks is .0100 plus .0005, equals .0105 inch. It will be understoodthat distances less than .0001 inch may be approximated by setting theinner dial 15 between the two dial divisions, it being readily possibleto interpolate by the eye to within one fifth of a dial division.

As hasl already been indicated, the two gauge devices illustrated areduplicates of one another, save in their specific relations to thecommon supporting frame structure.

In using the device as a go-no go gauge, the knob I1 or both the knobs|l and |B' are rotated until the spacing between the gauge blocks |56and |58' is the same as the maximum allowable size of the article undertest. The knob |1 or both the knobs |1 and I8 are then rotated until thespacing between the gauge blocks |56 and |58 corresponds to the minimumtolerance limit in the size of the article. Each article under test isthen passed down between the gauge blocks of the two units. If thearticle fails to enter and pass between the blocks |56' and |58', it istoo large and is rejected. If the article passes between the gaugeblocks |56 and |58' and also passes between the blocks |56 and |58 it isrejected as being too small. If it passes the first pair of gauge blocksbut will not pass the second it is accepted as falling within theallowable tolerances It is a distinct advantage of the device that itmay beset for testing articles of any size within its scope ofadjustment. Furthermore, any

I wearing away of the surfaces of the gauge yblocks may be Vreadilycompensated for by adjusting the screws |50 and |50.

` While I have illustrated my invention as including a stepped cam as aspacing` means for effecting diilerent positions for the operated rod ormember 2l, each of scribed differs uniformly in thickness from apreceding one of said cam steps, it 4will be understood that for somepurposes these cam portions may have any desired different thicknessesto meet the requirements of different purposes of use, whether thelimited amount of movement of the lever or operating member L is equalto the diierence between successive thicknesses or not. It will furtherbe understood that my invention is adapted for use where lesser degreesof accuracy of movement are permissible than for the uses described; forexample, for the pur pose of the relatively general grading or groupingof objects as to size, or the resonant selection of radio stations froma relatively small group of stations such as the broadcast band, thehigh degree of accuracy described may not be required; in such cases thespacing means or cam C need not be provided with the balls 90, but maybe an integral structure made from a single metal block, with a degreeof accuracy, in any case, that is commensurate with the intended purposeof the structure.

I have described what I believe to be the best embodiments of myinvention. I do not wish, however, to be confined to the embodiments setforth, but what I desire to cover by Letters Patent is set forth in theappended claims.

I claim:

1. In combination, an operating member having a limited amount offinely-graded and continuous movement, an operated member in line withsaid operating member for operation thereby, means tending to move theoperated member toward said operating member, a spacing member havingportions of different thicknesses for insertion selectively between saidoperating member and said operated member, first means for selectivelyinserting a desired portion of said spacing member between saidoperating member and said operated member, second means for moving saidoperating member through said limited movement, and a xed gauging memberin line with said operated member, whereby diierent spacings of saidoperated member from said fixed gauging member may be effected by saidspacing member and each of said dilerent spacings may be changed by saidoperating member, the spacing member and operated member havirminterengaging cam surfaces so that the operated member may be cammedaway from the operating member in response to mere rotation of thespacing member.

2. In combination, an operating member having a limited amount ofiinely-graded and continuous movement, an operated member in line withsaid operating member for operation thereby, means tending to move theoperated member toward said operating member, a spacing member havingportions of different thicknesses for insertion selectively between saidoperating member and said operated member, rst means for selectivelyinserting a desired portion of said spacing member between saidoperating member and said operated member, second means for which camsteps as de-` moving said operating member through said limitedmovement, a xed gauging member in line with said operated member,whereby different spacings of said operated member from said xed gaugingmember may be eiected by said spacing member and each of said differentspacngs may be changed by said operating member, a first dial indicatingthe amount of movement of said operating member, and a secondcomplementary

